Vol. 65.] ANNIVERSARY ADDRESS OF THE PRESIDENT. XCV 



A single continent might present exceptional conditions, we will 

 therefore next turn to South America. The data at our disposal 

 relating to the rivers of this continent are very imperfect. Our 

 knowledge of the composition is confined to a few isolated analyses. 

 The results calculated from these are as follows : — 



River. 



Table III 



Area of Basin. 

 2,50J,000 



Discharge. 



527-951 



188-746 



32137 



Sodium. 

 2,475,000 



La Plata 



Uruguay 



1,600,000 



12,170,000 

 514,230 





748-834 



15,159,230 



The average quantity of sodium per cubic mile in this case 

 is 21,470 tons. Using this number in connexion with Joly's 

 estimate, we obtaiu 101 millions of years as the age of the 

 Ocean. 



The total rainfall of South America is 7,297 cubic miles, as 

 estimated by Murray ; and this, multiplied by 0-222, gives 1824 

 as the total run-off. Of this, 749 cubic miles enter into our 

 estimate, which is based therefore on about two- fifths of the total 

 discharge. 



A study of the more important rivers of Europe affords the 

 following results : — 



Table IV. 



Na Na 



River. Discharge, (including NaCl). (excluding NaClJ. 



Seine, Paris 3-5207 105,100 44,060 



Loire, Orleans 2-00 (?) 76,000 



Bhone, Geneva 1-9308 39,375 34,428 



Elbe, Tetschen 2-4090 88,930 41,400 



Danube, Vienna 13\S621 160,230 85,040 



Klarelf, Sweden 1-6360 14,970 12,800 



Indaself, „ -4200 35,430 2,883 



Fyris, „ -0840 1,773 



Dwina, Archangel 26-5000 1,826,000 



Bhine, Cologne 163923 259,300 ■ 246,470 



68-7549 2,607,108 467,081 



1 In the case of the Amazon I have used Franklaud's analysis, tabulated by 

 Clavke, op. cit. p. 74 (B) ; in the case of the La Plata, an analysis by J. J. 

 Kyle, Clarke, p. 75 (A) ; and in the case of the Uruguay, an analysis also 

 by Kyle, Clarke, p. 75 (D). In all cases the discharge is quoted from Murray. 



